Rotary pump



Nov. 15,' T927. 1,649,256

, A. c. vRoEssLER ROTARY PUMP Filed April 2, 1927 2 Sheetsfsheet 1 mandwy 6T @0m/af Nov. 15, 1927.

A. C. ROESSLER ROTARY PUMP Filed April 2. 1927 2 Sheets-Sheet 2 nuentoz dma/Ida; ,Paws/en Patented Nov. l5, 1927.

UNITED STATES PATENT OFFICE.

AMANDUS C. ROESSLER, 0F LAKEWOOD, OHIO, ASSIGNOR TO THE ROTARY MACHINE ENGINEERING COMPANY, 0F CLEVELAND, OHIO, A CORPORATION OF OHIO.

ROTARY PUMP.

Original applications med February 10, 1923, Serial No. 818,173, and August 19, 1926, Serial No. 130.185.

Divided and this application led April 2, 1927. Serial No. 180,554.

This invention relates to new and useful im rovements in pumps and more particular y to the type of pump comprising a casing having an approximately cylindrical chamber, a rotor or piston cylinder mounted in said casing and 1n close contact with a portion of the wall of said chamber and a sliding blade carried by said rotor.

The object of this invention is to provide a rotary ump which shall be smooth 1n. action andp practically free Vfrom pulsations Another object is to provide a rotary pump which shall be reversible in action and which can be fabricated in a practical manner without the use of packing and packing glands.

Another object of my invention is to provide such aconstruction in a pump of the type set forth as will eliminate the back pressure in the pump which retards the operation and causes hammering andundue vibration.

Another object of my invention is to provide a pum which can be cheaply produced, which will be durable in operation and very efficient. l

Another object of my invention is the provision of new and improved means for packing the end of the piston blade.

A further object of my invention is to provide such an arrangement of parts asy will eiectually prevent the iiuid, which is being pumped, from being ,compressed while passing throu h :the pump chamber.y v

With tlesev objects in view andy with the intention of securing other advantages whichI will hereinafterv ap ear, my invention con-` sists in certain novelpfeatures of construction and combination of parts described in the specification, particularly pointed out in the claims and illustrated in the accompanying drawings. v i

Referring to the accompanying drawings Fig. 1 is a central vertical sectional view of a pump embodying my invention; Fig.y 2 is a section on line 2 2, Fig. 1; Fig. 3 is a vertical sectional view similar to F-ig. 1 and showing a slight modification; F ig. 4 is an enlarged sectional view of one end of the blade; Fig. 5 is a side View of the blade part- Again referring to the drawings 3 repre sents the casing of the pump which is in the form of a cylinder and is mounted on an in.

tegrally formed base 4. At each end of the i cylinder is formed an annular flan e 5. The end plates or cylinder heads are s own at 6 and 7 and these lates are secured to the cylinder or casing y means of bolts 9 which screw into the ilanges 5 on the casing. On the outer face of each of the cylinder heads is formed a series of` radially disposed webs or fins, shown at 11 and 12. These webs both reinforce the heads and also serve to radiate the heat generated through the operation of the pump and keep the pump in a sufficiently cool condition to prevent the freezing of the movable parts.

On the inner face of each head or end plate is formed a seat shwn at 13 and v14;, and at the center of each seat is formed a bearing, indicated at 15 and 16. The bear# ing 15 is referably closed at its `outer-end, as at 17, t ereby eliminating the necessity of packing said bearing.

The pump chamber is shown at 19 but the bore is not truly cylindrical, the dotted lines indicating the true circle and the full lines.

divides the pump chamber into substantially ls mmetrical halves and the points where this 11ne cuts the top and bottom of the pump chamberare concentric, that is to say, they are equal distances from the point where the line X-X intersects the line 2-2 and as before stated the dotted line indicates the circle described from this point whereas the actual bore is slightly different upon each side of the median line 2 2. In this pump chamber thus bored I employ a rotating blade more fully described hereinafter and it is essential that this blade should contact at all times at both of its ends with the walls of the cylinder andas the blade which I propose to use is fixed in its length it is obvious that thisblade constitutes a movable chord-and as the rotor which carries this blade is mounted eccentrically with reference to the cylinder the proper curvature of the bore can be mathematically obtained from the eccentric relation of the rotor to the bore and the length of the chord. This curve is known as a limaon curve and in Fig. 6 I have shown one manner of generating the curve of the bore 19 as is known in the art.

The rotor or piston carrying member 20 is, in general, cylindrical in form and is of such length that it extends from side to side of the chamber and the ends thereof fit snugly in the seats 13-and 14 in the cylinder' heads. The rotor is provided at one end with a stud shaft 21 which extends into the blind'bearin 15 and at its other end with a driving sha t 22 which extends 'through the bearing 16 and may be provided with a drum or other means, not shown, for driving the rotor. The general arrangement of the rotor with respect to the case is such that the rotor is in close contact with a portion of the wall at the top of the chamber'at all times. In the rotor is formed a slot 25 which passes through the axis of the rotor and the length of said slot'corresponds to the length of the pump chamber. In the slot 25 is slidably mounted a blade 26 the width of which is approximately equal to the length of the pump chamber and the length of said blade is such that both ends of said blade are always in contact with the walls of said chamber. rEhe blade is preferably made of steel and in the end of each blade is formed a semi-circular or concave seat 27. In each seat 27 is arranged a strip of packing material 28. In formingthis packing strip I take a rod of packing material which 4is circular in cross-section and having the same radius as the arc of the seat in the end of the blade. I then cut away a portion at one side of the rod above the center line thereof and then impart a curvature to the face, thus formed on the rod, corresponding to the general or average curvature of the wall of the pump chamber. This strip is then set into the seat in the end of the blade so that the base or ortion of the strip opposite the truncate face lits into said seat and the side portions project beyond the seat and the face thereof abuts against the wall of the chamber. It will readily be seen that owing lo this construction the strip is free to rock inl its seat as the blade revolves so that the face of the packing strip will at all times conform and press tightly against the wall of the pump chamber. Furthermore as the packing rocks one way or the other it will automatically increase or decrease the length of the blade and will therefore provide for the ever' changing radius of curvature of the wall of the chamber' or any probable imperfection therein and-will compensate the wear on the wall of the chamber. Also as said actresses packing strip has a definite side area projecting beyond the end of the blade, it will follow that when the fluid is being forced through the pump the pressure of the fluid will act against the side of the packing strip and cramp the strip against its seat great-ly increasing the efficiency of the. packing.

The intake port 30 is preferably formed at the top of the intake side of the chamber and the outlet port 31 is arranged on the opposite side of the chamber. The relative arrangement of the two ports is such that as one end of the piston blade passes the intake port the other end of the blade will be starting to travel across the outlet port and therefore the outlet port is opened for the escape of fluid back of the forward end of the blade as soon as the rearward end of the blade begins to act on said fluid. Consequently no compression can take place within the pump chamber. Also during a portion of the rotation of the rotor both ends of the piston blades act at the same time to expel the contents of the pump directly through the outlet port, because the forward end of the blade will be forcing fluid through the outlet port all the time it is passing across the outlet port and the rearward end of the blade will at the same time be forcing fluid through the outlet port back of the forward end of the blade.

As before mentioned the arrangement is such that a portion of the surface of the rotor for the full length of the rotor is always in gas or liquid tight, contact with a portion of the wall of the chamber. It therefore follows that as soon as the forward end of the blade passes or clears the outlet port a closed pocket is formed ahead of the blade. lVhen the pump is in operation this pocket will be filled with gas or liquid and the only chance for` it to escape is between the end ofl the blade and the wall of the chamber. This pocketing of the gas ori/'liquid causes a. continual pounding of the pump and ultimately results in loosening the pump from its mounting and injury to the driving mecha` nism. To obviate this difficulty I form an open duct o r groove 35 in the top wall of the pump chamber at the outlet side of said chamber. This groove extends longitudinally of the chamber'and in close proximity to the line of contact between the rotor and the wall of the chamber. A subsidiary outlet or vent passageway 36 is formed in the wall of the pump chamber and one end of this passageway communicates with the duct 35 and the other end communicates with the outlet passage from the outlet port 31. The fluid which would otherwise be trapped finds a ready means of escape by the way of the 'pockeang of the uuid isenareiy elim-limited 'together with the hammering caused there by, rendering the operationof the pump noiseless and greatly increaslng the durability of the pump.

and 2, that is to say, the 'bore of the cylinderv is constructed upon a limaon curve andthe details of the generation of this curve .will be more fully described hereinafter. This casing has its ends closed by means of platesV securely bolted to the casing, and formed with bearings for the rotor D, the rotor being cylindrical inshape similar to thatillustrated in Figs. 1 and 2.

The intake or suction opening F is located at one end of the casing and the outlet or dischargeopening G is preferably arranged diametrically opposite the opening F. The opening F communicates with the passage F and the inlet or suction port F 2 cut in the v wall of the cylinder establishes communication between the inlet or Suction passage'in the bore ofI the pump. The rotor D has a slot or opening H cut therein for the blade I. At each end of the blade is mounted a rocker K which contacts with vthe curved surface of the pump cylinder or bore. The ends of the blade are grooved and provided with an undercut J andin these grooves are mounted the rockers K which are free to oscillate as the rotor revolves. This oscillation is produced by the pressure of the fluid against the front face of the rocker and/or by the outer ends of the rocker making a contact with the pump bore during rotation and it will be seen that unless the friction or contact surface between the blade and rockers is less than that between the rocker and bore free;

oscillation will be plrevented holding the rockers rigid in whic case they would bind against the bore and prevent rotation of the rotor and for that reason the grooves are undercut so that there is less surface of the rocker in contact with the end of the blade than with the bore of the cylinder.

The ports are located insuch a manner that the. inlet port is closed before the outlet v port opens, the outlet port being indicated at G and in this manner all back pressure from the suction is preventedvand likewise com-' pression of the `fluid in the pump chamber. A certain amount of lead may be given so that the blade travels, say the width ofthe rocker after closing the suction `port and before reaching the discharge port. In this case the discharge port must open at the moment that the distance between the bore and rotor at the lower edge of the rocker is the same as at the other end of the blade that is between the bore at the suction side and the rotor. If this relationship is not maintained hammering will occur wlth considerable vibrations. .l

The ends vof thel blades being provided withrocke'rs in'undercut grooves the friction between the rocker and blade is reduced to a point below the friction between the rocker ends and bore and consequently these rocker ends will always turn suiiiciently to maintain a working contact between the blades and the bore and inasmuch as the blades with rockers attached thereto are of' .,i

constant length and as the bore is constructed upon the limaon curve previously referred to there will be the proper Working contact during the entire movementof the blades and irrespective of the direction of rotation.

In Fig. -6-1 have illustrated a diagram for the generation of the curve which is as follows: 40, 40 and 41, 41 indicate two lines crossing each other at right angles at the point 42 and from this pomt 42 is 'described a circle 43. Through the line 40, 40 is drawn line 44, 44 parallel with the line 41 and the distance between the lines 41 and l44 is the amount of eccentricity existing' between :the

rotor and the bore of the casing., On the line the radius of the circle 43. A line drawn through the various points 49 will give the correct limaon curve which is the curvature of the bore of the cylinder and as the rotor ino turns within the cylinder driving the blades,

vthe movement of the blades back and forth through the slots will cause the central point ofl each blade to describe a circle similar to 45 and in this manner the blades will be held in constantv 'contact with vthe walls of the Apump cylinder due to the fact .that their lengths are fixed and the curvature of the bore is upon the curve indicated.v From the above it will be noted that the bore of the pump is not in the Vform of a true circle at any point or for any sensible arc whatever. At each end of theopening H in the rotor, thesurface is cut back as shown at X in Fig. 3. These cut backs flatten the rotor at the points where they are located, thus allowing foreign matter to pass over the top from the discharge to suction side of the pump when the blade is in the vposition where the rotor makes contact with the bore.

In rotary pumps as heretofore constructed the difficulties in operation have resulted from imperfections in manufacture and imperfections or errors of design. In order to compensate for errors in manufacture the ieu appliances are not sufficient to provide. forV the combined errors of manufacture and the departure from theoretically'correct designs.v For this reason centrifugal force, springs and flexible devices have been employed for the purpose of securing blade contact with theipump barrel. By constructing the bore upon the `limaon curveas hereinbefore set forth, -it is possible to dispense with various forms of flexible devices and employ a blade of ixed dimensions having roller contacts vwith the bore of the pump and which will efectivelyprevent pounding and slippage.

This application is a division of my pending applications, Serial No. 618,173, filed.

February 10, 1923, and Serial No. 130,185, filed August 19, 1926. vand the subject-matter thereof not described and claimed herein is reserved forsaid applications.

What l claim is:

1. A rotary fluidY pressure machine comprising a casing having --inlet and outlet ports and a chamber in communication With said ports, the peripheral wall of said' cha-mber conforming to a limaon curve, a rotor mounted eccentrically Within said chamber, a rigid blade member reciprocable diametrically in said rotor, andmovable non-yielding packing means mounted inthe opposite ends of the blade and adapted to make a sealing contact with the vWall of said chamber in all positions of said blade.

2. A rotary fluid pressure machine comprisiiig a. casing having inlet and outlet ports and a chamber in communication With said ports, the peripheral Wall of said chamherconforming to a limaon curve, a rotor mounted eccentrically Within said chamber, a rigid blade member reciprocable diametrically in said rotor, and rigid packing means rockably mounted in the opposite ends of the blade and adapted to make a sealing contact with the Wall of said chamber in all rpositions of said blade.

3. A rotary fluid pressure machine comprising a casing having inletand outlet ports and a chamber in communication with said ports, the peripheral wall of said chamber conforming to a limaon curve, a rotor mounted eccentrically Within said chamber, a rigid blade member reciprocable diamet- "i'ically in said rotor, and pivoted packing means mounted-in the opposite ends of the blade and held in place by the chamber wall,

'said packing being adapted to contact with the wall of the chamber in advance of the median plane of the blade.

A4:. A rotary fluid pressure machine comprising a casing having inlet and outlet ports and a chamber in communication With said ports, the peripheral Wall of said chamber conforming to a limacon curve, a rotor mounted eccentrically Within said chamber,

a rigid blade member reciprocable diametrically in said rotor, and pivoted packing means mounted in the opposite ends'of the blade and having a chamber contacting face curved to conform approximately to the curvature of the cylinder Wall.

5. A rotary pump comprising a casing, a rotor eccentrically mounted in said casing, and a blade carried by' the rotor and sliding therethrough and including pivoted packing means at the extremities thereof, the casing being bored on a limaon curve, generated by a chord, whose length is equal to the length of the blade on its medial line, and whose movement is such that its center describes a circle Whose diameter is equal to the amount of eccentricity of the rotor with reference to the casing along the medial line, and whereby the pivoted ends of the blade make contact With the bore of the casing at all points of rotation.

6. A rotary fluid pressure device comprising a chamber shaped to conform to a limaon curve and having a rotor eccentrically mounted for rotation therein and inlet and outlet ports spaced apart angularly on the side of the chamber toward Which the rotor is mounted, a blade extending through the i'otor and provided with seats at its ends, rockers mounted in said seats for movement toward either side of the blade, said rockers haivng Working faces adapted to contact with the Wall of the chamber at their leading edge whereby pressure from fluid being pumped is exerted on the forward edge of the rockers to maintain said leading edge in close contact therewith.

7. A rotary fluid pressure device comprising a chamber having 'closed ends and a peripheral Wall shaped to conform to a limacon curve, a rotor mounted therein with its axis of rotation passing through the cliordal center of sai'd limaon and parallel to the principal axis of the chamber, a blade extending through the rotor transversely of its axis, .said blade being shorter than the chordal length of said limacon and provided With seats at its extremities, and rockers mounted in said seats for pivotal movement toward either side of said blade, said rockers having working faces conforming to the interior of said chamber adapted to bear against it in either direction of rotation.

8. A rotary fluid pressure device comprising a chamber the peripheral Wall of which is shaped to conform to a` limacon curve, a rotor eccentrically mounted in said chamber in fluid tight contact with the Wall of said chamber and parallel to the principal axis of said chamber, a blade carried by said rotor and slidable therethrough and including movable packing means joui'naled in the extremities thereof. inlet and outlet ports communicating with said chamber on opposite sides of said rotor, said outlet port including a porin the chamber and consequent hammering. l

9. A rotary fluid pressure machine comprising a casing having inlet andl outlet ports and a chamber in communication with said ports, the peripheral Wall of said chamber conforming to a limaon curve, a rotor mounted eccentrically within said chamber a rigid blade member reciprocable diametrically in said rotor, and movable non-yielding packing means mounted in the opposite ends of the blade and adapted to make a sealing contact with the wall of said chamber in all positions of said blade, the mounting of said packing means being such as to reduce the frictonal contact between said packing means and blade member.

10. A rotary fluid pressure device come prising a chamber shaped to conform to a limaon curve and havlng a rotor eccentrically mounted for rotation therein, and inlet and outlet ports spaced apart angularly on the side of the chamber toward which the rotor is mounted, a blade extending throui the rotor and provided with seats at its en rockers mounted in said seats for movement toward either side of the blade, said rockers having working faces adapted to contact with ,the wall of the chamber at their leading edge whereby pressure from fluid being pumped is exerted-on the forward edge of the rockers to maintain said leading edge in close contact therewith, said outlet port including a portionl in the chamber wall terminating in close proximity to the line of contact between the rotor and bore of the chamber. for the purpose of increasing the capacity of the pump and prevent hammering. n c

11. The combination with a pump chamber, the bore of which is a limaon curve generated on a circle, the diameter of which is equal to one-half the difference between .the diameter of the rotor and the diameter of the pump chamber on the median line, of a rotor mounted eccentrically to the pump chamber, a slidably mounted blade in the rotor, -oscillating rockers mounted in the ends of the blade the ends of the blade being cut away to provide seats for the rockers and the rocker being so A shaped that pressure from the fluid being pumped is exerted upon the forward edge of said rocker, said bladev sliding through the center Aof rotation, inlet and outlet ports arranged so that the inlet port is closed substantially at or slightly before the outlet port opens, to avoid compressing the fluid within the casing or the production of pressure before the outlet port opens. A

12. The combination with a pump chamber, the bore of which is a limaon curve generated on a circle thediameter of which is equal to one-half the difference between the diameter of the rotor and the pump chamber on the median line, of a rotor mounted eccentrically to the pump chamber, a slidably mounted blade in the rotor, oscillating rockers mounted in the ends of the blade, said blade sliding through the center of rotation, inlet and outlet ports so arranged that the inlet ortis closed substantially at or slightly gefore the outlet port opens, thereb avoiding compressing the iluid within t e pump chamber, or the prduction of pressure before the outlet port opens. i

In testimony whereof, I have signed my name to this specificatlon.

AMANDUS o. ROESSLEB. 

